The present invention relates to a general purpose video special effects system and method therefor.
Most video special effect systems using a video random access memory (RAM) are cumbersome and difficult to organize for any out of the ordinary special effects. For example, a typical special effect is a "paint by numbers" scheme where a frame buffer is used. Here the images are limited to computer produced art work such as drawings, bar graphs, pie charts, etc. A color look up table is utilized. Such a system available on a single integrated circuit chip is produced by Inmos Corporation under Model IMS G170.
Most prior systems make no provision for passing video signals through the effects device at a full video rate in real time. They allow only the output of computer drawn imagery as discussed above or a single snapped frame from a video camera. Those that do have the ability to pass real time digital video are limited to, for example, one type of predetermined special effect. In any case, it is cumbersome and difficult for the operator to organize another special effect. Examples of the foregoing are illustrated in U.S. Pat. Nos. 4,266,242 to McCoy and 4,353,092 to Bailey.
Dan Sandin disclosed another technique with his "Image Processor," a patch programmable analog image processing synthesizer which implemented a variety of video processing functions in physical hardware modules. See the publication "Dream Machines" published by Computer Lib. in 1974. All of these modules were discrete analog devices which were connected together like a "Moog" type music synthesizer.
Bill Etra, with Steve Rutt, developed the Rutt-Etra video synthesizer. This device allowed alteration of video images by processing applied to the video in and X and Y deflection of a precision CRT which was then rescanned by a video camera. Etra, with Don Day, developed the Video Modular System. This system provided a modular approach to digital processing hardware and included software written by Day to control the processing of the real time image.
Steina and Woody Vasulka, working with Jeffrey Schier, demonstrated real time processing of digital video through dedicated logic hardware (arithmetic and logic units) and frame buffers with special programmable address generators. This system did rotation and other special effects. Both the Etra and Vasulka concepts are discussed in general in a 1984 Paris publication by CINE-MBXA/CINEDOC entitled "STEINA ET WOODY VASULKA: VIDEASTES." See also "Afterimage" Vol. 11, No. 5, Dec. 1983 published by Visual Studies Workshop of Rochester, N.Y.